KnowledgeBase Archive

An Archive of Early Microsoft KnowledgeBase Articles

View on GitHub

Q161721: Interphase EISA Adapter Doesn’t Support EISA Bus Preemption

Article: Q161721
Product(s): Microsoft Windows NT
Version(s): 3.5,3.51,4.0
Operating System(s): 
Keyword(s): kb3rdparty kbhw kbHardware
Last Modified: 25-FEB-2002

-------------------------------------------------------------------------------
The information in this article applies to:

- Microsoft Windows NT Workstation versions 3.5, 3.51, 4.0 
- Microsoft Windows NT Server versions 3.5, 3.51, 4.0 
-------------------------------------------------------------------------------

SYMPTOMS
========

The Cisco/Interphase EISA FDDI/CDDI adapters do not support EISA bus preemption.
This may result in the adapter's being incompatible with PCs using a dual/split
PCI/EISA I/O bus.

The following models of Cisco/Interphase EISA FDDI/CDDI network adapters:

- WA-C321T-PC

- WA-C323T-PC

- WA-C326T-PC

- WA-C328T-PC

can cause intermittent system resets or crashes with STOP: 0X0000000A.

Some PC systems that are known to exhibit this symptom include:

- IBM PC Server 320 CYO

- Compaq Proliant series (some models)

- ALR Revolution Quad6


CAUSE
=====

The Interphase EISA FDDI/CDDI adapter requires guaranteed access time (GAT) to
function properly. PCs that implement EISA bus preemption without also
supporting GAT will experience problems. The symptom is intermittent and occurs
when both the FDDI adapter and a PCI device are active.

The adapter design predates implementation of the EISA bus preemption feature as
described in EISA specification 3.12 (PCI/EISA systems shipped after 9/1/95).

In PCs with both a PCI and an EISA bus, PCI devices are allowed access to system
memory even if the EISA bus has been granted control. Because the adapter
requires GAT, and because PCI devices are able to de-assert the EXRDY (external
ready) signal to the EISA bus, the adapter will stall and not finish its
transfer to memory.

WORKAROUND
==========

If you are experiencing this problem, first contact your system vendor to see if
your PC supports GAT mode. If your PC does not support GAT, consider the
following two workarounds:

- Reduce adapter transfer burst size from 64 bytes to 32 bytes. This reduces
  burst transfer time and has a positive effect on some systems. This can be
  changed in the registry entries for the drivers (C320tnt.sys). To make this
  change, follow the steps listed below:

  WARNING: Using Registry Editor incorrectly can cause serious, system-wide
  problems that may require you to reinstall Windows NT to correct them.
  Microsoft cannot guarantee that any problems resulting from the use of
  Registry Editor can be solved. Use this tool at your own risk.

  1. Run Regedt32 and select the HKEY_LOCAL_MACHINE Window

  2. Go to SYSTEM\CurrentControlSet\Services\c320tnt1\parameters

  3. Change the "BurstSize" from 63 (3F hex) to 31 (1F hex)

- An alternative for adding FDDI connectivity, for systems with PCI slots, is
  the Interphase PCI/FDDI 5511.

  NOTE: Don't use an EISA adapter in PCs with active PCI devices. Use the
  adapter only in PCs that have an EISA bus.

MORE INFORMATION
================

Additional information can be obtained from Interphase at the following URL:

  http://www.iphase.com/Public/AppEng/prodsup/c32x/EISAFDD2

  Interphase Corporation
  13800 Senlac
  Dallas, TX 75234-8823

  Technical Support: +1.214.654.5555
  E-mail: intouch@iphase.com
  World Wide Web: http://www.iphase.com
  Anonymous FTP: ftp://ftp.iphase.com

The products discussed here are manufactured by Cisco and Interphase, vendors
independent of Microsoft; we make no warranty, implied or otherwise, regarding
the products' performance or reliability.

The third-party contact information included in this article is provided to help
you find the technical support you need. This contact information is subject to
change without notice. Microsoft in no way guarantees the accuracy of this
third-party contact information.

Additional query words:

======================================================================
Keywords          : kb3rdparty kbhw kbHardware 
Technology        : kbWinNTsearch kbWinNTWsearch kbWinNTW400 kbWinNTW400search kbWinNT351search kbWinNT350search kbWinNT400search kbWinNTW350 kbWinNTW350search kbWinNTW351search kbWinNTW351 kbWinNTSsearch kbWinNTS400search kbWinNTS400 kbWinNTS351 kbWinNTS350 kbWinNTS351search kbWinNTS350search
Version           : :3.5,3.51,4.0

=============================================================================

THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY.